‘I’m Really quite a fan of your work,’’ a young man tells the brother-and-sister protagonists of the dismal “Hansel and Gretel: Witch Hunters.’’

It’s a sentiment unlikely to be shared by audience members — especially if they’re unlucky enough to shell out 20 bucks to watch this direct-to-video-grade dreck in murky IMAX 3-D.

January is a traditional dumping ground for Hollywood studio mistakes, and this one’s a real stinker that’s been mouldering on the shelf at Paramount after a planned opening last March was postponed.

When a flick’s been whittled down to just 80 minutes before the end credits, it’s a sure sign of a dump job designed to suck up as many dollars as possible before lethal word-of-mouth spreads.

Co-produced by Will Ferrell, this is an exceedingly dull and stillborn attempt to update the Brothers Grimm.

In this misguided sequel, the grown-up Hansel (Jeremy Renner) and Gretel (lovely Gemma Arterton) have gone into the witch-hunting business after shoving one into an oven as kids.

Armed with anachronistic machine guns, grenades and tasers, the brother and sister turn up in the Bavarian village of Ausburg, where the locals are about to burn a redhead they believe is a witch responsible for the disappearance of a number of children.

Much to the annoyance of the sheriff (Peter Stormare), they set the redhead free and set out to capture the actual culprit, the Great Witch (Famke Janssen) before she can convene a witch convention.

Or something like that.

All sort of generic fantasy tropes and cheesy special effects are boringly trundled out by Norwegian director Tommy Wirkola (“Dead Snow’’), whose screenplay could probably fit on a napkin.

Nothing makes a whole lot of sense in this incoherent movie, whose director’s philosophy seems to be: When in doubt, cut somebody’s head off.

Janssen, who wears some ghastly makeup, is on record as saying she did “Hansel and Gretel: Witch Hunters’’ to pay off her mortgage.

I wonder what excuse Renner, an Oscar nominee for “The Hurt Locker’’ and “The Town,’’ could possibly offer for his third thankless (if highly remunerative) role in a row — following “Marvel’s the Avengers’’ and “The Bourne Legacy.’’

Renner looks vaguely embarrassed throughout, particularly when he’s required to give himself an injection of 18th-century insulin because of his childhood indulgence in a candy-covered house.

When the Great Witch’s trail leads them back to that same house for the mindlessly anti-climactic climax of “Hansel and Gretel: Witch Hunters,’’ Hansel quips, “You’ve gotta be f–king kidding me.’’